The trend in the circuit protection industry is currently toward complete circuit protection which is accomplished by the addition of supplemental protection apparatus to standard overcurrent protective devices, such as molded case circuit breakers. In the past, when such auxiliary protection apparatus or other circuit breaker accessories were combined with a standard circuit breaker, the accessories were usually custom-installed at the point of manufacture. The combined protective device, when later installed in the field, could not be externally accessed for inspection, replacement or repair without destroying the integrity of the circuit breaker interior. U.S. Pat. No. 4,894,631 describes a molded case circuit breaker containing an actuator-accessory unit which provides a wide variety of circuit protection accessory options. This patent is incorporated herein for purposes of reference and should be reviewed for its description of the state-of-the-art of such circuit breakers and accessory devices.
U.S. Pat. No. 4,913,503 describes a reset mechanism for a lower ampere-rated circuit interrupter usually employed as a "branch" circuit interrupter within industrial power distribution systems downstream from a higher ampere-rated "main" circuit interrupter. When actuator-accessory units are used within the higher-rated circuits, the actuator-accessory units are incapable of providing sufficient force, per se, to overcome the holding force of the powerful operating mechanism springs. Additional tripping force is provided by a supplemental tripping mechanism which interacts with the actuator-accessory unit through a sequential resetting system to insure that the actuator-accessory unit becomes reset before the main operating mechanism is reset.
U.S. Pat. application Ser. No. (41PR-6785) describes a sequential resetting system that interfaces between the tripping mechanism and the actuator-accessory unit of a higher-rated molded case circuit interrupter to insure that the actuator-accessory unit becomes reset before the main operating mechanism. U.S. Pat. application Ser. No. (41PR-6800) describes the supplemental tripping mechanism that interacts with the actuator-accessory unit to provide sufficient tripping force to articulate the circuit interrupter operating mechanism. Additional accessory devices, such as the bell alarm described in U.S. Pat. application Ser. No. 311,794 filed Feb. 17, 1989, and that described within U.S. Pat. application Ser. No. (41PR-6807) are often required with such circuit interrupters containing a sequential resetting system and a supplemental tripping mechanism. All of these Applications are incorporated herein for purposes of reference. In order to use standard accessory designs over a wide range of circuit interrupter ampere ratings, some means must be provided to operate the accessory devices within both higher as well as lower-rated circuit interrupters and some means must be provided to interface between the actuator-accessory and the supplemental tripping mechanism for tripping the interrupter operating mechanism and re-setting the actuator-accessory unit.
One purpose of this invention accordingly, is to describe an actuator-accessory interface unit that interacts between the actuator-accessory unit in the interrupter cover and the supplemental tripping unit within the interrupter case. Another purpose of this invention is to provide means for accurately aligning the actuator-accessory interface unit with the supplemental tripping mechanism when the interrupter cover is attached to the interrupter case.